Java Backend Developer
Summary
Build and maintain high-performance Java backend services for a regulated payments platform, handling transaction processing, settlements, and financial integrations.
We are looking for a Java Backend Developer to join a production‑critical backend platform within the payments domain. The role focuses on building and maintaining high-performance backend services in a regulated, high‑scale environment, supporting transaction processing, settlements, financial reporting, and integrations with internal and external systems. Strong hands‑on Java experience and comfort working with mature, mission‑critical systems are essential.
Responsibilities
- Design and develop backend services using Java 17+
- Build scalable components supporting transaction data, settlements, and reporting
- Integrate backend services with relational databases and internal financial systems
- Develop secure REST APIs aligned with compliance and security standards
- Collaborate closely with product owners, analysts, architects, and QA teams
- Optimise system performance, reliability, and data processing efficiency
- Participate in code reviews, testing, and continuous improvement activities
- Support platform modernisation and resolve production issues
- Contribute to clean code practices and long‑term platform scalability
Requirements
- 3–5 years of commercial Java backend experience
- Strong knowledge of Java 17+ and modern backend frameworks
- Hands‑on experience with relational databases (SQL; Oracle / PL/SQL preferred)
- Experience working with microservices and distributed systems
- Solid understanding of REST API design and system integrations
- Experience working in Agile delivery teams
- Good communication skills and ability to work in international environments
- Work in a multinational environment on international projects
- Long‑term B2B contract with a stable project pipeline
- Hybrid working model (remote with 1 day per week in the Warsaw office)
Nice to have
- Experience in fintech, payments, banking, or other regulated domains
- Exposure to CI/CD pipelines, DevOps practices, or containerised environments
- Experience with messaging or event‑driven architectures
- Background in high‑volume or real‑time systems